1. Establish the metabolic pathways of polyprenol synthesis by isolating and characterizing other prenyltransferases and to determine the role of the farnesyl-PP synthetase in the synthesis of dolichols and coenzyme Q. Measure the concentration of key metabolites of sterol and polyprenol synthesis in normal tissue and in tissues in which the rate of cholesterol synthesis has been perturbed. 2. Determine the turnover of prenyltransferase in normal tissues and cells as well as in tissues and cells in which the rate of cholesterol synthesis has perturbed. Determine the relative amounts of active and inactive forms of this enzyme under the above conditions and evaluate the significance of the active and inactive forms, especially in the neonate. 3. Evaluate the mechanism by which the diet of the neonate changes the mode of regulation of cholesterol biosynthesis in the adult.